For example, cancer cells and tumor-antigen presenting cells are shown to express high levels of coinhibitory receptor ligands (PD-L1, PD-L2 and many other) with relatively low levels of costimulatory receptor ligands (CD80 and CD86) in the tumor microenvironment to promote T cell anergy (40–43). The gene discussed is PDCD1LG2; the disease is neoplasm.